Exhaust Size
Choosing the right exhaust system size
A common misconception is that the larger the diameter of an exhaust system, the better the performance... but bigger isn't always better.
Systems that are too large for the capacity/horsepower of the engine can actually hurt performance.
As a rule, switching to a performance system that is 1/4" to 1/2" larger than the standard system combined with free-flowing muffler designs will provide you with the best overall horsepower increases.
To determine which pipe diameters will be the best for your exhaust system, first decide what RPM range you would like your engine to peak perform at.
When reading the table below, leaning toward the smaller diameters within the e CID will provide low to mid-range RPM torque whereas the larger diameter will provide mid to high RPM.
| Engine CID | Single System | Dual System | Horsepower |
| 150-200 |
2" (51mm) |
2" (51mm) 2" (51mm) 2" (51mm) |
100 150 200 |
| 200-250 |
2.25" (57mm) |
2" (51mm) 2" (51mm) 2.25" (57mm) |
150 200 250 |
| 250-300 |
2.25" (57mm) 2.5" (64mm) 3" (76mm) |
2" (51mm) 2.25" (57mm) 2.5" (64mm) |
200 250 300 |
| 300-350 |
3" (76mm) 3" (76mm) 3.5" (90mm) |
2.25" (57mm) |
250 300 350 |
| 350-400 |
3" (76mm) 3.5" (90mm) 3.5" (90mm) |
2.5" (64mm) 2.5" (64mm) 2.5" (64mm) |
300 350 400 |
| 400-450 |
3.5" (90mm) 4" (101mm) 4" (101mm) |
2.5" (64mm) 3" (76mm) 3" (76mm) |
350 400 450 |
| 450-500 |
4.5" (115mm) 4.5" (115mm) 4.5" (115mm) |
3.5" (90mm) 3.5" (90mm) 3.5" (90mm) |
300 |
